Dust-cap for pneumatic tires



w. 0. vxvARTTAs. nus cAP'FoR PNEUMATIC mEs.

APPLICATION FILED MAR. 25| 1920.

Patented July 19, 1921.

MIR,

JN VENTOR W/u/A/v 0 V/vAnrr/as narran WILLIAM O. VVARTTAS, OFWEEI-IAWKEN, NEW JERSEY.

i t Y :DUST-CAP FOR PNEUMATIC HERES.

To all w/wmvt may concern: Y

Be ity known' that l, WILLIAM O. Vivi-inrrns, a citizen of the UnitedrStates, and a resident of Weehawken, in the vcounty of Hudson andStateof New Jersey, have ini vented certain new and useful improveof thecharacter Pneumatic Tires,

ments in Dust-Caps yfor a full, clear, and

of which the following' is exact. description.

Among the principal objects which the present invention has in view are:to diminish the time usually required for installing in service the dustcaps associated with the valve stems of pneumatic tires; to prevent theaccidental displacement of said dust caps; and to simplify and cheapenthe construction of the improved dust cap.

Dra/wings.

Figure 1 is a longitudinal section of a dust cap constructed andarranged in accordance with the present invention, showing inconjunction therewith a valve stem mentioned, the section being taken ason the line 1-1 in F ig. 2;

Fig. 2 is a cross section of the cap and stem, the section being takenas on the line 2 2 in Fig. 1.

Description.

Heretofore dust caps which have been employed for the protect-ion ofvalve stems, and for the parts of the tire associated therewith, havebeen furnished with a screw-threaded section of a pitch corresponding tothe 'screw-threaded sections 9 on the valve stem, and at either side ofthe Hat faces 10 to secure the proper alinement thereof in service. rlhetime required to screw the dust cap down over the relatively long stemhas been considerable, with the result that it has added a great deal tothe time necessary for the inflation of tires of the charactermentioned. rlhis difficulty has been one that the automobilist has foundirksome, with the result that in many instances the dust caps have beenomitted, either intentionally or unintentionally, after the tires havebeen inflated.

To avoid this the present dust cap slides over the stem and does notengage directly the threaded sections 9. The threads of these sections 9are, however, utilized as engaging points for a rubber packing orarovided on the said stems J jack 11, which isdisposed within thehousing section 12 on the dust cap. The section 12 is increased indiameter over the section 13, and provides at the junction therewith, ashoulder 14 to form an abutment against which the or crowded. The jackis compressed by a ram 15, which is externallyy threaded to enwage aninternal thread provided within the housing section 12. As seen best inFig. 2 of the drawings, the ram 15 has an elongated opening 16, shapedin correspondence with the valve stem having parallel sides for asliding lit on the flat sides 10 of the valve stem, The ends of theopening 16 are extended to avoid the threaded sections 9 of the valvestem.

From the foregoing it is obvious that when the rubber jack 11is notcompressed, the dust cap may be moved lengthwise of the valve stem atwill, there being none other than a free sliding yengagement between thedust cap and the valve stem.

When, however, the dust cap is rotated about the ram 15, the ram iscaused to travel within the housing section 12 toward the shoulder 14 byreason of the screwthread engagement existing between said housing andthe said ram.

rlhe rubber gasket or jack 11 is thereby compressed lengthwise, thematerial thickening or expanding laterally in compensation therefor. Theinner wall of the. .jack 11 crowds upon and lits into the threads of thesections 9, thereby anchoring the dust cap to prevent the lengthwiseInovement thereof in the valve stem. A half turn of the dust cap isusually suflicient to compress the jack 11 sufliciently to force thesame into engagement with the stem. lf closer engagement is desired,this is obtained by continuing the rotation of the dust ca To avoidadhesion ofthe gasket or jack 11 to the ram 15, with the consequenttendency to drag or twist the said gasket or jack,there is provided athin metal washer' 17, which operates as a shoe or protective facingVfor the said ack.

Vhen it is desired to remove'the dust cap the said cap is reverselyrotated to cause the ram 15 to travel toward the retaining flange 18with which the housing 12 is provided, The iiange 18 is spun over thechamber formed by the housing 12 jack 11 is pressed PATENT @FFICE;

Y Specification of Letters Patent. Pdgqgnijd July iglg, Applicationfiled March 25, 1920. Serial $10,368,492. 4 i v body closed said stem;

Thereafter the said i'am is prevented 'fromn passing out of the saidhousing.

Y Y Claims;

LA dust Cap for service with `a pneumatic valve embodying a mutilatedcylindrical steimsaidcap comprising a tubular at one end for enfoldingfreely an open-ceiitered'ram held perf manently in said body, theopening `in said ram being shaped in eoriespondenee'with said stem fornoiieiotatively' -to move freely lengthwise thereover; an open-centeredyielding packing member vsupported Within' said body and for distentionto engage said stem; means operatively connecting said body said body isrotated.

matie valve embodying zlated Cylindrical stem, said cap comprisingholding said ramon said vstemV and said' ram for moving said body towardsaid ram for distending said member When for servieerwith a pneu` athreaded muti- 2. A dust Cap a tubular body closed at one end forenfolding freely said stem; an open centered ram permanently mounted insaid body and having screw-thread engagement there- With, said ramlbeing adapted to movef freely lengthwise of said stem and to be heldnon-iotatively thereby;

packing member interposed( between said ram and said cap to becompressed thereby and means for preventing an edge of said packingmember from'engafring said stem.

f WiLLiAM l o; VVRTTas.

a soft bodied Y

